Angle Bisectors

Front

What is an angle bisector?

Back

An angle bisector is a line or ray that divides an angle into two equal parts.

Front

If an angle bisector divides an angle of 60 degrees, what is the measure of each of the two angles formed?

Back

30 degrees.

Front

In triangle ABC, if ray AD is the angle bisector of angle A, what can be said about the measures of angles BAD and CAD?

Back

They are equal.

Front

What is the relationship between the angles formed by an angle bisector and the original angle?

Back

The angles formed by an angle bisector are congruent to each other.

Front

If m∠JKM = 22 degrees and KM bisects ∠LKJ, what is m∠LKJ?

Back

44 degrees.

Front

If m∠DEJ = 5x + 7 and m∠JEF = 8x - 8, and EJ bisects ∠DEF, how do you find x?

Back

Set 5x + 7 equal to 8x - 8 and solve for x.

Front

What does it mean for two angles to be congruent?

Back

Two angles are congruent if they have the same measure.

Front

How can you determine the measure of an angle when given its bisector?

Back

You can use the property that the bisector divides the angle into two equal parts.

Front

What is the formula to find the measure of an angle when given the measures of the angles formed by its bisector?

Back

If m∠1 and m∠2 are the angles formed, then m∠ = m∠1 + m∠2.

Front

If angle A is bisected and m∠A = 80 degrees, what are the measures of the two angles formed?

Back

40 degrees each.